1. Field of the invention.
The present invention deals with materials which retard emulsion or foam formation in an oil.
2. Description of the art.
Benoit in U.S. Pat. No. 2,813,129 issued Nov. 12, 1957 describes high molecular weight polyglycols and a method for their production. Harding et al in U.S. Pat. No. 4,617,984 issued Oct. 21, 1986 describes polytetra (methylene oxide) or poly (trimethylene oxide) homopolymers having molecular weights of from about 300 to about 1,000.
Login et al in U.S. Pat. No. 4,245,004 issued Jan. 13, 1981 describes block copolymer lubricants for synthetic textile fibers which are derived from tetramethylene oxide (tetrahydrofuran) and ethylene oxide. Uchinuma in U.S. Pat. No. 4,248,726 issued Feb. 3, 1981 describes a high-viscosity refrigerator oil obtained from a polyglycol oil such as polyoxypropylene glycol or an alkyl ether thereof.
U.S. Pat. No. 4,263,167 to Mago described poly (alkylene oxide) compositions which are stated to be resistant to oxidative degradation and which inhibit the corrosion of ferrous metals. Harold in U.S. Pat. No. 3,634,244 issued Jan. 11, 1972 describes alkylene polyethers which are soluble in mineral oil and having a molecular weight of 10,000 or greater which may be utilized as a viscosity index improving additive in a lubricating oil composition.
Riemenschneider in U.S. Pat. No. 3,004,837 issued Oct. 17, 1971 describes two-cycle engines and lubricant additives which are useful in the formulation of such fuels. The particular additives which Riemenschneider is utilizing include polypropylene glycol having a molecular weight of at least 600. U.S. Pat. No. 3,509,052 issued to Murphy Apr. 28, 1970 describes polyoxyalkylene glycols in lubricants.
Jacobson et al in U.S. Pat. No. 3,382,055 issued May 7, 1968 describes polymers of 1,2-epoxy alkanes having 10 to 18 carbon atoms which may be utilized as pour depressants for middle distillates and light lube oil stocks.
McCoy in U.S. Pat. No. 3,789,003 issued Jan. 29, 1974 describes a process for coverting normally oil-insoluble, high molecular poly (alkylene) oxides into oil-soluble complexes by treatment with alkylated phenol-type compounds. Herold in U.S. Pat. No. 3,829,505 issued Aug. 13, 1974 describes hydroxy terminated polyethers which are stated to be useful as non-ionic surface active agents, lubricants and coolants.
Latos in U.S. Pat. No. 3,847,828 issued Nov. 12, 1974 describes the working of non-ferrous metals through the use of a lubricant containing a polyglycol. Davis in U.S. Pat. No. 3,919,093 issued Nov. 11, 1975 describes lubricant compositions containing anti-wear amounts of mixtures of an alkylene oxide polymer and sulfur. The use of certain 1,4-butanediol polymers is described in a du Pont brochure entitled Terathane.RTM. Polyether Glycol marked as E-77911 11/85 (2M).
The present invention is particularly concerned with antiemulsion/antifoam properties of certain polymers in a lubricating oil. In particular the polymers prevent or minimize foaming and emulsion formation in a IID engine test and in field test conditions prone to produce emulsions.
To the extent that any reference cited in this application is applicable to the present invention it is herein specifically incorporated by reference. Percentages and ratios are by weight unless otherwise indicated. Temperatures are in degrees Celsius, and pressures are in KPa gauge unless otherwise indicated. To further define and illustrate the invention ranges and ratios given herein may be cross-combined.